MP 1,1-5,1 Mac Pro 3.1 (2008) Random shutdown

[kanoriano]

My mac pro 2008 after upgrade dual x5482 and 64gb ram, ssd, wifi card, working well 2 years.
But at this moment can randomly shutdown. When i turn on it, mac can work, or turn off again after 1-2 sec.
When im left 2 memory sticks on top board, mac work stable. All memory was tested, and have no errors. Top and bottom memory board also work properly.

Anyone know what happens with mac 3.1 ? Im think PSU have problems..

 

[Macschrauber]

I'd vote also for PSU or a heat issue. Try with a tool like Macs Fan Control to blast the fans and then add Memory. If it survives there is a heat issue. And your Mac Pro is in trouble.

 

[kanoriano]

12V line #1,2,3 to low.. guess 100% PSU.. sad

 

[kanoriano]

That was not PSU. Just best apple connectors

 

[ikir]

That was not PSU. Just best apple connectors
View attachment 2041097View attachment 2041098

The shutdown after few minutes or during boot is a common issue on Mac Pro 3.1. Are you saying the psu is not the cause? That connector is indeed on psu.